Spurious lung perfusion ventilation defect on planar ventilation-perfusion scan detected by SPECT imaging

Pulmonary embolism (PE) is a preventable cause of morbidity and mortality which needs prompt recognition. Ventilation-perfusion (V/Q) scan is a well-established diagnostic test for evaluation of suspected PE. We report a 32-year-old woman with history of rheumatologic disease and acute dyspnea, who was referred for V/Q scintigraphy. The planar images revealed multiple mismatched defects throughout both lungs. SPECT images showed that only one of the defects was real, the others were caused by patient’s elevated right arm. Our case showed a V/Q pitfall with emphasis on importance of SPECT imaging in V/Q scintigraphy.